"""PRD §5.4 NFRFM005 — two-eyes self-double-approval guard.

Wraps the existing ``approve_disbursement_request`` (services.py:374-ish) with
the new ``require_two_eyes`` check so the same actor cannot approve a record
twice, even across tiers. Both an explicit budget approval and a disbursement
approval path are exercised.
"""
from __future__ import annotations

from datetime import timedelta
from decimal import Decimal
from unittest.mock import patch

import pytest
from django.contrib.auth import get_user_model
from django.core.exceptions import ValidationError as DjangoValidationError
from django.utils import timezone

from apps.core.audit.models import AuditLog
from apps.core.audit.tasks import persist_audit_log
from apps.core.permissions.roles import UserRole
from apps.rims.finance.models import Budget, BudgetLine
from apps.rims.finance.services import approve_budget_total, require_two_eyes
from apps.rims.grants.models import Application, Award, GrantCall

User = get_user_model()


@pytest.fixture(autouse=True)
def _sync_audit():
    with patch("apps.core.audit.tasks.write_audit_log.delay", side_effect=lambda **kw: persist_audit_log(**kw)):
        with patch(
            "apps.core.audit.mixins.transaction.on_commit",
            side_effect=lambda fn: fn(),
        ):
            yield


@pytest.fixture
def finance_manager_user(db):
    u = User.objects.create_user(email="fm.2e@example.com", password="pw-6c")
    u.role = UserRole.FINANCE_MANAGER
    u.save()
    return u


def _budget(applicant_user, institution) -> Budget:
    call = GrantCall.objects.create(
        title=f"6C-2e call {timezone.now().timestamp()}",
        slug=f"6c-2e-{int(timezone.now().timestamp() * 1000) % 10_000_000}",
        call_type="grant",
        opens_at=timezone.now() - timedelta(days=200),
        closes_at=timezone.now() + timedelta(days=10),
        status=GrantCall.Status.PUBLISHED,
    )
    app = Application.objects.create(call=call, applicant=applicant_user, institution=institution)
    award = Award.objects.create(
        application=app,
        amount=Decimal("20000"),
        currency="USD",
        awarded_at=timezone.now(),
        project_end_date=timezone.now().date() + timedelta(days=365),
    )
    budget = Budget.objects.create(award=award, name="2E budget", currency="USD")
    BudgetLine.objects.create(budget=budget, label="Line", amount=Decimal("5000"))
    return budget


@pytest.mark.django_db
def test_first_approval_succeeds(applicant_user, institution, finance_manager_user):
    budget = _budget(applicant_user, institution)
    approve_budget_total(budget, actor=finance_manager_user, tier="finance_manager")
    # No exception raised — first approval is allowed.


@pytest.mark.django_db
def test_second_approval_by_same_actor_blocked(
    applicant_user, institution, finance_manager_user
):
    budget = _budget(applicant_user, institution)
    approve_budget_total(budget, actor=finance_manager_user, tier="finance_manager")
    with pytest.raises(DjangoValidationError) as excinfo:
        approve_budget_total(budget, actor=finance_manager_user, tier="finance_director")
    assert "Two-eyes" in str(excinfo.value)
    # PRD §5.4 NFRFM005 — block must be audited.
    assert AuditLog.objects.filter(action="TWO_EYES_VIOLATION_BLOCKED").exists()


@pytest.mark.django_db
def test_require_two_eyes_helper_direct(
    applicant_user, institution, finance_manager_user
):
    budget = _budget(applicant_user, institution)
    # No prior approval — should not raise.
    require_two_eyes(budget, actor=finance_manager_user)
    approve_budget_total(budget, actor=finance_manager_user, tier="finance_manager")
    # Now require_two_eyes should raise.
    with pytest.raises(DjangoValidationError):
        require_two_eyes(budget, actor=finance_manager_user)